Method of operating a washing machine



y 1963 H. W..GESCHKA ETAL 3,

METHOD OF OPERATING A WASHING MACHINE Filed July 12, 1961 Fig! i F ig.4

RNVENTORS HUGO WERNER GESCHKA JOSEF LEONARD GILLESSEN ALBERT HEIDENREICH United States Patent 3,099,022 METHGD 0F OPERATING A WASEHNG MAC I Hugo Werner Geschlra, Angermund, Bezirk Dusseldorf, Josef Leonard Gillessen, Unterhach, near Dusseldorf, and Albert Heidenreich, Lintorf, Bezirk Dusseldorf, Germany, assignors to Maschinenfabrik Peter Pfenningsberg G.m.b.l-l., Dusseldorf, Germany Filed July 12-, 1961, Ser. No. 123,491 Claims priority, application Germany Jan. 25, 1961 Claims. (61. 8158) This invention relates to a washing process which is intended for washing machines operating on the flow principle, in which the Washing drum containing the articles to be washed is intermittently and, preferably, reversibly driven.

In general, the characteristic feature of the flow process is that fresh water is supplied to the vessel containing the washing drum not only during the wetting and rinsing stages but also during the actual washing stage, in which the articles to be washed are treated both mechanically, by the movement of the drum, and also chemically and thermally by the washing liquid, while at the same time a corresponding amount of used wash ing liquid flows away through an overflow. This flovv process which, as compared with the customary washing with a stationary washing liquid, represents washing with rinsing simultaneously superimposed on it, has the object of conducting away the dirt, which is freed from the articles being washed and passes into the washing liquid, as soon as possible from the washing liquid, in order that in this way the washing liquid in contact with the fabric may remain relatively clean and, therefore, the washing eflect may be improved.

It will be understood, however, that the flow process, as compared with the customary washing with a stationary washing liquid, not only requires an increased consumption of Water, but also necessitates an increased consumption of washing agent and heat owing to the used washing liquid being continuously, or at least intermittently, discharged through the overflow. In the flow process, therefore, it is important to supply the fresh water both in quantity and also in time so that water, washing agent and heat are economised and good wash ing eifect is also obtained. Therefore, numerous proposals' have already been made with this object. It is known to supply the fresh water continuously to the washing drum container during the wetting and rinsing stage, and during the washing stages to supply it either continuously but in reduced quantity per unit of time or, a

in separate batches or portions. It has further been proposed to work with a continuous supply of fresh water during the wetting stage and with separate portions of fresh water during the rinsing stage, in order in this way to achieve an improved removal of dirt during the rinsing stage. it is also not new to supply the fresh water to the drum container in separate portions during the washing stage, because this also promised a better removal of the impurities in the washing liquid. Finally, it is also known to work with a continuous supply of fresh water during the wetting and rising stages and to limit the supply of fresh water during the washing stage to the first section of this stage. In this case also the fresh water is only supplied to the washing liquid in the first part of the washing stage and after this the washing process is completed in a stationary washing liquid, This so-called two-stage Washing process has the advantage, as compared with other known washing processes, that with it a considerable saving of washing agent and also of heat is effected and the greater part of the particles of dirt which are detached from the articles being washed during "ice the washing process is removed from the washing liquid at an early stage.

Exhaustive experiments have now proved that it is very important for the economy of the flow process and for obtaining the best washing effect that the supply of fresh water should be coupledin a definite manner with the rotary movements of the washing drum, because there is a close connection between the mechanical effects of the drum and the inflowing fresh water. Thus, it has been found that, for obtaining a good washing effect and at the same time a maximum saving of washing agents, heat and water, the best results are obtained when the fresh water is supplied in separate portions or batches but, in accordance with the invention, in such a way that this supply in separate portions takes place in the wetting and rinsing stages during the rotary movements of the washing drum but in the washing stage it takes place when the washing drum is stationary. The advantageous effects of supplying the fresh water in this manner will appear from the following consideration. In the wetting stage the freshwater supply is used not only for filling the container of the washing drum but, in particular, for sufficiently wetting the articles to be washed. This wetting eifect is intensified by the movements of the drum because in this way the articles being washed are intimately mixed with the fresh water supplied. This efiect would, of course, also take place if the supply of fresh water were continuous. However, this would have the disadvantage that during the times when the washing drum is stationary the fresh water which is then supplied Would flow through the washing drum somewhat rapidly by the shortest path, so that, considering the wetting effect aimed .at in this stage, it would leave the washing drum practically without being used. The same conditions also hold good for the rinsing stage, because it is also important in this stage to mix the fresh or rinsing water passing through the drum as intimately as possible with the articles being washed in order to wash away the particles of dirt adhering to the articles, whereas if the flow of rinsing water is cut off when the drum is stationary, water is again economized. As compared with these conditions, however, in the washing stage the conditions are exactly reversed. In this stage the fresh water supplied is mainly intended only to carry away the upper layer of the washing liquid and the particles of dirt which originate from the articles and collect in this layer. This carrying away of the upper layer of the liquid can be best effected with little disturbance when the washing drum is stationary, the more so because in this stage the particles of dirt in the washing liquid float upwards and collect on the surface of the washing liquid. If, on the other hand, the fresh water were .also supplied to the washing drum in the washing stage during the rotary movements of the drum, the carrying away or discharge of the upper surface layers of the washing liquid and, therefore, the removal of the impurities would be considerably interfered with and the washing effect aimed at would be impaired or would even become illusory.

According to a further feature of the invention the duration of the supply of fresh water in portions during the wetting and rinsing stage corresponds to the intervals in the supply of fresh water in portions during the washing stage in which the duration of the supply in portions again corresponds to the intervals between the supply of fresh water in portions in the wetting and rinsing stages. The ratio between the duration of the supply of separate portions of fresh water taking place during the wetting and rinsing stages to the intervals between them,is preferably about 4: 1. It has been found in practice that particularly good washing results are then obtained if the amount of the individual portions of fresh water per unit of time in all sections of the washing process, that is to 3 say in the wetting, rinsing and washing stages, is kept constant.

According to a further feature of the invention, the regular sequence of the portions of fresh water supplied during the washing stage can be interrupted for a definite period one or more times in order to suit the supply of water to the existing washing conditions. In this way a fine regulation of the amount of water supplied is possible. This is desirable, for example, when only '2 kg. of articles to be washed are contained in a washing machine having a capacity of about 3 kg. of dry articles. Also a water inlet valve which forms part of .all household types of washing machines and by which the amount of water passed per unit of time is always the same, can be used. The portions of fresh water which are supplied intermittently at definite intervals for maintaining the flow of water can also be regulated during the washing stage in dependence on the size of the charge of the washing drum and/or on the capacity of the type of washing machine being used. Regulation of the supply of water during the washing stage is also important because the washing water is heated in this stage. If the amount of water supplied is too great, then too much heat is lost when the washing liquid enriched with particles of dirt flows away. If, on the other hand, the amount of washing liquid is too small, too few coarse particles of dirt are discharged from the washing drum; in both cases the results of the wash would be unsatisfactory.

The washing process according to the invention is particularly suitable for those flow washing machines in which the washing process is sub-divided into two working stages and in which the washing liquid is heated by a heating device built into the machine. In this case, in the first washing stage, a definite amount of fresh water is supplied in the first washing stage to the container for the washing drum which is filled up to the level of the open overflow and the same amount of washing liquid enriched with particles of dirt flows away from the washing drum container, whereas in the second washing stage the supply of fresh water is cut 013? and the washing liquid is further heated to the final temperature and the washing process is completed. In a washing process of this nature, therefore, the supply of fresh water during the first stage of the washing process takes place in separate portions, the regular sequence of which can be interrupted for a suitable period for the purpose of adapting the supply of fresh water to the capacity of the washing machine and to the charge of the washing drum at the time. After a predetermined time, or when the prescribed temperature of the washing liquid is reached, a second washing stage begins in which the supply of water is completely cut olf and the further treatment takes place in a stationary bath of liquid. In the rinsing which follows fresh water is again supplied in portions to the container for the washing drum but now the duration of the periods of supply and the intervals between them is reversed as compared with the first stage of the process.

Further features of the invention are illustrated diagrammatically, and by way of example, in the accompanying drawing in which:

FIGURE 1 is .a flow diagram of a fully automatic washing machine operating in accordance with the process of the invention;

FIGURE 2 is a part elevation of the washing machine 111 section; V

- FIGURE 3 is an electric circuit for the fresh water supply valve; and

FIGURE 4 is a perspective view of the upper part of a washing machine provided with a handle for adjusting the amount of the water supply.

Referring to the drawing, in the flow diagram illustrated in FIGURE 1, the time t for the duration of the entire washing process is plotted along the abscissa and the supply 'of fresh Water in litres per second is plotted along the ordinates. The reference t represents the wetting and pre-rinsing stage, t the actual washing stage, t the rinsing, and t the following spin drying stage. The actual washing stage t is sub-divided into two sections 1 and t In the section t the so-called flow washing stage, fresh water is supplied to the container of the washing drum and a corresponding amount of used water flows away through the overflow of the washing machine. In the section t the supply of f esh water is cut oh? so that the treatment takes place in a substantially stationary washing liquid, which is further heated at the same time. The supply of fresh water takes place in separate portions which are indicated in the diagram by the hatched rectangles 29. As is hereinafter described in greater detail, the washing machine which is used for carrying out the process is provided with a single fresh water supply valve and with a washing drum which is reversibly driven during the wetting, washing and rinsing stages at a comparatively low speed but during the spin drying stage rotates in one sense at a considerably greater speed.

As will be seen from FIGURE 1, during the supply of fresh water for the wetting and pre-rinsing stage t the water inlet valve is repeatedly opened for about 12 seconds after which it is closed for approximately 3 seconds. Duringthe open periods of the valve, portions of fresh water are supplied to the washing drum. During the supply of these portions 29 the drum rotates, whereas it is stationary in the intervals between them. Owing to the rotary movement of the washing drum, the fresh water which is supplied eifects thorough wetting of the articles to be washed, and owing to the supply of water being cut ofi when the drum is stationary water is econornised. Further, the short interruptions in the inlet of water dur-' ing the wetting and preliminary rinsing phase are also of advantage, because groups of eddies which form in the region of the water inlet in the drum container and in which particles of dirt are accumulated, are dissipated and the particles pass into the pre-rinsing liquid and are drained away.

After the wetting and preliminary rinsing stage is complete, at the beginning of the actual washing stage t the sequence of the opening and closing of the water inlet valve is reversed, so that now the water inlet valve is opened at intervals of 12 seconds for a time of 3 seconds. Then the supply of the individual portions of water coin cides, as regards time, with the time when the reversible washing drum is stationary, so that with the great economy of water the upper layers of the washing liquid which are enriched with particles of dirt are drained out of the washing drum container through the overflow.

In order to adapt the amount of water supplied in portions during the washing stage t to the capacity of the washing drum and also to its charge of articles to be washed, the regular sequence of the supply of portions of fresh water in this stage can be interrupted one or more times for a definite period Preferably, the sequence of the supply of these portions of water is such that they are uniformly distributed over the washing phase t Towards the end of the washing stage t the supply of fresh water is cut oif and the washing now takes [place with a practically stationary washing liquid although, owing to the repeated drum movements, a certain amount of consumed washing liquid is discharged through the overflow on the drum container or overflows at this place. Thus, in the second section t of the washing stage t the discharge of the washing liquid through the overflow is considerably reduced, whereby a considerable economy in washing agent and particularly in heating energy is obtained. As the heating device remains switched-on, the temperature of the washing liquid rises quickly so that now, since the greatest part of the impurities were removed during the first washing stage 1 the washing process is carried to completion with good efficiency.

Following the washing stage t the first rinsing stage t takes place in which the fresh-water valve is now open for relatively long periods as in the wetting and pre-rinsing stage t and closed for short periods. In this stagealso the supply of the portions of fresh water as regards :time is such that they coincide with the rotary movements of the washing drum, whereas the intervals between the supply of portions of fresh water coincide with the times when the drum is stationary during its reversing movements. Following the first rinsing stage t the first spin drying stage 2, takes place in which an outlet valve in the bottom of the container of the washing drum is opened or a pump is operated and the washing drum is rotated at the high speed necessary for spin drying. After this, further rinsing stages, followed by spin drying, can take place and also in these rinsing stages the supply of portions of fresh water takesplace in the above-mentioned manner, namely in time with the reversing movements of the washing drum.

'FIGURE 2. illustrates. the main parts of a washing machine which is suitable for carrying out the process of the invention. A washing drum 33 which rotates about an approximately horizontal axis is mounted in a container 34 which is fixed to the casing of the washing machine, which is not illustrated, or mounted on a vibration-damping support. A heating body 37, which is switched-on at the beginning of the washing stage 1 or before a warm rinsing, is fitted in a trough or recess 36 in the container 34. The single water inlet 38 in which the water valve 35 is fitted is disposed near the trough 35. In the bottom of the trough 36 there is also the main outlet 39 which, however, only comes into action when the spin drying begins, the remainder of the washing liquid being then pumped out of the chamber 41 of the washing drum by a pump 40' which is fitted in the discharge pipe 49. An overflow 42 is provided in the rear wall of the container 34, through which overflow an amount of washing liquid corresponding to the amount of fresh water supplied during the washing stage can flow away. The capacity of the overflow 42 is, however, limited, so that during the wetting and rinsing, owing to the lmge supply of water which then takes place, the level of the liquid rises, for example up to the dotted line 43. At this place there is a larger outlet 44 through which the rinsing liquid is conducted away.

In the washing machine in accordance with the invention, the flow of liquid during wetting, washing and rinsing always takes place upwardly from the bottom of the drum, as indicated by the lines of flow 45 in FIGURE 2. When the fresh water flows in, the stream meets the stream 46 or 49 in the container 34 which is produced in the washing liquid by the rotation of the reversibly driven dru-m 33 in the directions indicated by the arrows. Owing to this, eddies are formed near the fresh water inlet in the container 34, at 47 and 48. Impurities collect in these eddies and are not carried along by the stream of rinsing water. Owing to the periodic interruptions in the inlet of water, however, these eddies are repeatedly broken up and, therefore, the particles of dirt in them are taken along by the rinsing water and discharged.

FIGURE 3 shows a suitable circuit for the freshwater valve 35. The valve 35 is controlled by a magnet coil 50. In the leads to the coil 50 there are two switches which are connected in parallel and controlled, in dependence on time, by the program regulator, namely a switch 55 which is closed during the wetting and rinsing stage, and a switch 58 which is closed during the washing stage. The switch 55 is controlled by a cam 56 and the switch 58 by a cam 59, both of which cams can be mounted on a common shaft driven from the program regulator. By means of a periodically-operating reversing switch 52 the current leads associated with the switches 55 and 58 are alternately connected to the coil 50 of the fresh-water inlet valve 35. The periodicallyoperating reversing switch 52 is controlled by a cam 51 which rotates synchronously with the set of reversing contacts for the motor which drives the drum and are not illustrated, or it may be identical with them. The cam .51 is preferably so constructed that it connects the reversing. switch 52 sequentially for 12 seconds with the contact 53 leading to the switch 55, and for v3 seconds with the contact 54 leading to the circuit 61. As already mentioned, the switch 55 is closed during the wetting and rinsing stages, so that it then connects the current supply through -the contact 57. During this time the switch 58 is open. The switch 58 is closed during the washing stage by the cam 59 controlled by the program regulator, thatis to. say the current supply is connected through the contact 60. During the washing stage the switch 55, is open. Asshown in FIG. 3, therefore, during the wetting and rinsing stages while the reversing switch 52 is ,in contact with the contact 53 the freshwater valve 55 is opened for a period of 12 seconds, whereas in the other position of the reversing switch 52, when it is in contact with the contact 54, the valve is closed. These conditions are exactly reversed during the washing stage, because then the switch 58 is closed and the switch 55 is open.

A circuit breaking switch 63 which is operated by a cam 62 is provided in the branch lead 61 containing the switch 58. The switch 63 serves the purpose of interrupting the sequence in which portions of water are supplied during the washing stage by predetermined periods. By means of it, with the ratio of the times of opening and closing of the fresh-water valve 35 remaining the same, the supply of fresh water can be regulated during the washing stage in dependence on the capacity of the washing drum or the amount of its charge. With it also, the conditions may be adapted to suit the heating as well as to the cross-section of the waterpipe or the like. If the amount of fresh water is to be variable during the washing stage, then either the length of the cam 62 can be adjustable or an ordinary bi-metallic contact can be used in place of the cam 62, the times of opening and closing of the bi-metallic switch being adjustable. The circuit breaking switch 63 or its cam 62 can also be controlled by the program switch. Preferably, however, it is actuated by a time mechanism which can be adjusted by hand and operates independently of the program switch.

The washing machine illustrated in FIGURE 4 possesses, in addition to the usual handles or actuating knobs 64, 65 for setting the washing program and the temperature of the washing liquid, an additional handle 66 for adjusting the amount of the water flow. This handle 66 co-operates with the circuit breaking switch 63 or regulates the periods during which it is opened and closed. The handle 66 can be in the form of a rotary switch or a pressure key.

We claim:

1. In a method of operating an automatic washing machine in which fresh water is supplied during the wetting, Washing and rinsing stages in separate portions at intervals to a washing drum which is intermittently driven, and a corresponding amount of used liquid is discharged through an overflow, the improvement which comprises the step of controlling the flow of water so that the supply of portions of fresh water during the wetting and rinsing stages takes place during the rotary movements of the washing drum and in the washing stage when the washing drum is stationary.

2. The method of operating an automatic washing machine, comprising the steps of supplying fresh water during the wetting, washing and rinsing stages in separate portions at intervals to a washing drum which is reversibly driven, discharging a corresponding amount of used liquid through an overflow, and controlling the flow of water to said drum so that the supply of portions of fresh water during the wetting and rinsing stages takes place during the rotary movements of the washing drum and in the washing stage when the washing drum is stationary.

3. The method of operating an automatic washing machine as defined in claim 1, in which the duration of the supply of portions of fresh water during the wetting and rinsing stages corresponds to the intervals between the 7 supply of portions of fresh water during the washing stage and the duration of the supply of portions of fresh water during the washing stage corresponds to the intervals between the supply of portions of fresh water in the wetting and rinsing stages.

4, The method of operating an automatic washing machine as defined in claim 1, in which the duration of the supply of portions of fresh water during the wetting and rinsing stages corresponds to the intervals between the supply of portions of fresh Water during the washing stage and the duration of the supply of fresh water during the Washing stage corresponds to the intervals between the supply of portions of fresh water in the wetting and rinsing stages and the ratio of the duration of the supply of portions of fresh water during the wetting and rinsing stages to the intervals between them is approximately 4:1.

8 5. A method as defined in claim 1, in which the regular sequence of the supply of portions of fresh water during the washing stage is interrupted for the purpose of regulating the quantity of fresh water supplied to suit the washing conditions.

References Cited in the file of this patent UNITED STATES PATENTS Chamberlin June 12, 1951 2,635,446 Smith Apr. 21, 1953 2,676,088 Blide et al Apr. 20, 1954 2,677,259 Woodward et al. May 4, 1954 3,030,789 Rothenberger Apr. 24, 1962 3,073,668 Rothenberger Jan. 15, 1963 FOREIGN PATENTS 830,739 Great Britain Mar. 16, 1960 

1. IN A METHOD OF OPERATING AN AUTOMIATIC WASHING MACHINE IN WHICH FRESH WATER IS SUPPLIED DURING THE WETTING, WASHING AND RINSING STAGES IN SEPARATE PORTIONS AT INTERVALS TO A WASHING DRUM WHICH IS INTERMITTENTLY DRIVEN, AND A CORRESPONDING AMOUNT OF USED LIQUID IS DISCHARGED THROUGH AN OVERFLOW, THE IMPROVEMENT WHICH COMPRISES THE STEP OF CONTROLLING THE FLOW OF WATER SO THAT THE SUPPLY OF PORTIONS OF FRESH WATER DURING THE WETTING AND RINSING STAGES TAKES PLACE DURING THE ROTARY MOVEMENTS OF THE WASHING DRUM AND IN THE WASHING STAGES WHEN THE WASHING DRUM IS STATIONARY. 